Method and apparatus for producing fiber reinforced organic foam

ABSTRACT

Urethane plastic foam reinforced with glass fibers is provided, the glass fibers being combined with the plastic foam material prior to foaming. The foaming of the plastic material is physically controlled and restrained to achieve particular desired physical characteristics of the final product. By restricting the extent of foaming, and by using particular layers of fibers, high fiber concentration and more dense skin areas can be obtained in the foam; the fibers can also be initially distributed in a manner to increase their concentration near the surfaces of the foam body. Apparatus is provided for producing reinforced foam in a continuous manner and a method is also provided for combining the fiber reinforcement and the foamable plastic material in a manner such that the plastic material is disposed between two layers of the fiber reinforcement to assure proper distribution of the fibers in the foam. In a preferred form, the fibers are initially disposed in the foamable material in a manner to lie generally perpendicular to the primary direction of growth or rise of the foamable material so that the fibers are also generally perpendicular to the resulting elongate cells. The fibers also preferably are of particular lengths and diameters and present in optimum concentrations to achieve maximum reinforcement and strength in the final product.

United States Patent [191 Rood et al.

[ l- Feb. 18, 1975 METHOD AND APPARATUS FOR PRODUCING FIBER REINFORCEDORGANIC FOAM [75] Inventors: Leonard D. Rood, Columbus;

. Ronald E. Kissell, Alexandria, both of Ohio [73] Assignee:Owens-Corning Fiberglas Corporation, Toledo, Ohio [22] Filed: Mar. 6,1973 [21] Appl. No.: 338,486

[52] U. S. Cl 264/45.3,264/45, 425/4,

Primary Examiner- M. J. Welsh Attorney, Agent, or FirmCarl G. Staelin;John W, Overman; Allen D. Gutchess, Jr.

[57] ABSTRACT Urethane plastic foam reinforced with glass fibers isprovided, the glass fibers being combined with the plastic foam materialprior to foaming. The foaming of the plastic material is physicallycontrolled and restrained to achieve particular desired physicalcharacteristics of the final product. By restricting the extent offoaming, and by using particular layers of fibers, high fiberconcentration and more dense skin areas can be obtained in the foam; thefibers can also be initially distributed in a manner to increase theirconcentration near the surfaces of the foam body. Apparatus is providedfor producing reinforced foam in a continuous manner and a method isalso provided for combining the fiber reinforcement and the foamableplastic material in a manner such that the plastic material is disposedbetween two layers of the fiber reinforcement to-assure properdistribution of the 'fibers in the foam. In a preferred form, the fibersare initially disposed in the foamable materialin a manner to liegenerally perpendicular to the primary direction of growth or rise ofthe foamable material so that the fibersare also generally perpendicularto the resulting elongate cells. The fibers also preferably are ofparticular lengths and diameters and present in optimum concentrationsto achieve maximum reinforcement and strength in the final product.

7 Claims, 13 Drawing Figures mmrza: a m, v 3967, 494 sum am a METHOD ANDAPPARATUS FOR PRODUCING FIBER REINFORCED ORGANIC FOAM In one form, thefoamable plastic material is supplied in a liquid state between twolayers of glass fibers which can be continuously provided from supplyrolls/The foamable material can be supplied from a line which isreciprocated back and forth substantially over the width of the fibrouslayers. Cover sheets are also preferably located on the outer surfacesof the fibrous layers to protect components of the machine fromcontamination from the foam material as it penetrates into the fibrouslayers and foams to the outer surfaces thereof. To aid in thedistribution of the foamable ma I terial in the fibrous layers, thecombination is maintained in a restricted zone under some compressionduring initial foaming until substantially all of the fiber layers havebeen impregnated with the foamable liquid in its cream or initiallyfoamed state. As the foamable material subsequently foams, thecombination is directed between a pair of spaced conveyor belts whichpreferably are positioned apart a distance less than the thickness thecombination of foam and fibers would otherwise ordinarily reach ifallowed to foam unrestrictedly. In this manner, the resulting fiberreinforced foam body or slab has two major, flat, parallel surfaces inits final form. The product can be cut to any desired size after itemerges from the conveyor belts and the plastic material issufficiently'hard.

The fibers are generally oriented in directions parallel to the majorsurfaces of the layers while the-foam material foams or rises indirections perpendicular to the major surfaces. It has beendiscovered'that optimum properties are obtained when the cells of thefoamed material are elongate in the direction of rise or in a directionperpendicular to the major surfaces of the final slab, the foam beingstronger in this direction and weaker in directions parallel to themajor surfaces.

With the fibers disposed generally perpendicular to the elongation ofthe cells and parallel to the major surfaces of the slab, they providethe additional strength exactly where it is needed, in directionsparallel to the major surfaces of the slab. It has also been found thatemploying fibers of particular diameters and longer lengths improves thestrength of the foam. This occurs because the fibers tend to lie alongthe walls of the cells of the foam and provide better reinforcement thanwhen shorter fibers are used which tend to pierce the cell walls andextend through the cells.

Also in accordance with the invention, a foam prodslab substantiallyless than would otherwise occur with unrestricted foaming, the fibersalso are moved outwardly and concentrated more near the surfaces. Thisprovides greater impact resistance and compressive strength for theresulting slab or body than would otherwise occur. If desired, thefibrous layers used with the foam can initially besupplied so that thefibers are concentrated near the outer surfaces of these layers also toachieve concentration of the reinforcing fibers near the surfaces orskins of the slabs.

A foam product withgreater compressive or impact strength at thesurfaces can also --be achieved by using fibrous mats at the surfaces inaddition to themain layer or layers of fiber reinforcement in theinterior.

It is, therefore, a principal object of the invention to provide animproved fiber-reinforced foam body and a method and apparatus forproducing same.

Another object of the invention is to provide improved apparatus forcontinuously making fiberreinforced foam bodies.

A further object of the invention is to provide a method for making afiber-reinforced foam body.

Still another object of theinventio'n is to provide a fiber-reinforcedfoam body having the :reinforcing fibers located mostly in the cellwalls of the foam.

Still a further object of the invention is to provide a fiber-reinforcedfoam body having elongate cells and having reinforcing fibers disposedgenerally perpendicularly to the longitudinal extent of the cells.

Yet a further object of the invention is to provide a fiber-reinforcedfoam body having reinforcing fibers concentrated near the majorsurfacesor skins thereof.

Many other objects and advantages of the invention will be apparent fromthe following detailed description of preferred embodiments thereof,reference being made to the accompanying drawings, in which:

FIG. 1 is a somewhat schematic view in perspective, with parts brokenaway, of a line or apparatus for continuously producing afiber-reinforced foam body or slab;

FIG. 2 is a greatly enlarged view in perspective of fibers ofa fibrouslayer to be impregnated with foamable material;

FIG. 3 is a view similar to FIG. 2 of the fibers covered with foamablematerial in the cream state,. prior to foaming;

FIG. 4 is a view similar to FIGS. 2 and 3 of the fibers after thefoamable material has. substantially completed foaming;

Fig. 5 is a schematic view in vertical cross section taken through twolayers of fibers between which a foamable material has been placed;

FIG. 6 'is a view similar to FIG. 5 of the same components after foamingand with restrictive members limiting the extent of the foaming;

FIG. 7 is a view in vertical cross section similar to FIG. 6 but withthe fibers concentrated more at the surfaces or skins of the body;

FIG. 8 .is a view similar to FIG. 6 but with mats of fibers positionedat the outer surfaces of the body;

FIG. 9 is a fragmentary view in perspective of roof insulation embodyinga fiber-reinforced foam slab in accordance with the invention;

FIG. 10 is a view similar to FIG. 9 of slightly modified roofinsulation; v

FIG. 11 is a schematic view in perspective of apparatus for producing alayer of insulating material on a pipe or tank, by way of example; and

FIGS. 12 and 13 are schematic views of modified apparatus for applyingcompressive forces to the newlycombined foam and fiber combination.

Referring to the drawings, and particularly to FIG. 1,

' a line indicated at is suitable for continuously producing afiber-reinforced foam body. A flexible carrier or protective sheet 12 issupplied through the line 10 from a supply roll 14. The sheet 12 can beof paper or other inexpensive material and serves to carry the compositebody and to protect components of the line 10 from contamination by thefoam. The sheet can also form part of the final product if desired. Alower layer 16 of fibers is also supplied to the line 10 from a supplyroll 18. The fibrous layer.l6 is located above the lower sheet 12 withboth supplied between suitable rolls 20 and 22 located adjacent anopening 24 in an exhaust hood 26. A slight negative pressure ismaintained within the exhaust hood 26 by an exhaust fan (not The sheet12 and the layer 16 are directed under a' guide roll 28 and onto a belt29 with an organic foamable material 30 then applied to the upper orinner surface of the layer 16. This material is supplied through adischarge end 32 of a supply pipe 34 from a suitable source of supplyindicated at 36 in which the ingredients or components for the foamablematerial 30 can be proportioned and mixed. The components for thefoamable material can be supplied in two portions, one being anisocyanate, and the other being a polyol consisting of a base resin, anemulsifier, a catalyst, and a blowing agent, such as Freon 11B. Thesetwo basic portions are combined, in proper proportions at the supplysource 36 and immediately, fed through a stationary pipe 38communicating with the pipe 34. The pipe 34 is reciprocated transverselyof the layer 16 to supply the foamable material 30 uniformlythereacross, either as a stream, as shown, or as a spray. For thispurpose the reciprocated pipe 34 is slidably mounted on the stationarypipe 38 and moved by a link 40 which is pivotally connected to a cam 42driven by a speed reducer 44 and a suitable motor 46. The foamablematerial 3.0 preferably is not supplied completely to the edges of thelayer 16, however, since the material will expand outwardly to someextent as it foams.

After the foamable material 30 is supplied in the liquid state on thefibrous layer 16, a second fibrous layer 48 can be applied thereoverfrom a supply roll 50. It is with the roll 66 preferably being driven bya suitable drive 70. The rolls 64 and 66 are also adjustably' mountedfor vertical movement and for varying pressure by mountingmeans 71. Thedistance between the main conveyor belt 29 and the pressure belt 6.8 asmeasured at the beginning of the conveyor 62 preferably is such as tocompress the fibrous layers 16 and 48 to some degree but notexcessively. For example, a four inch layer might be compressed to athickness of about one inch. Stated another way, a fibrous layer or packwith foamable material therein reaching the cream state can becompressed to about one-fourth its original volume. If the compressiveforces are excessive, the fiber concentration will be too great and thefoamable material will collapse. In some instances, the fibrous layerneed not be compressed at all but only retained in shape while thefoamable material foams.

' The foamable material begins to foam or expand substantially at thetime it reaches its cream state or shortly thereafter. The blowing agentor freon evolves at this time because of polymerization and the heatinternally built up in the foamable material. The. compression on or theretention of the fibrous layers during this initial foaming aids inenabling the layers to be thoroughly imnot always essential to provide asecond fibrous layer but the foam can more readily and uniformlypenetrate the fibrous layer-if it is in the form of two thinner'layersthan one thicker one. When the fibrous layer exceeds a thickness ofabout 4 inches, the use of two thinner layers has been found to beadvantageous. An upper carrier sheet 52, which can also be a flexible,inexpenv To achieve thorough penetration of the foamable liquid in thefibrous layers, a combination of the carrier pregnated by the foamableliquid. By placing the second conveyor roller 66 a longer distance fromthe main conveyor belt 29 so that the belt 68 diverges from the belt 29,the impregnated fibrous pack is allowed to expand as foaming progresses.The foam cells thereby elongate in the direction of rise to providegreater strength in that direction than otherwise obtainable, thestrength in the horizontal direction being primarily provided by thefibers which tend to have a horizontal orientation. If elongate cells ina horizontal direction are desired, the second conveyor roller 66 can belocated closer to the belt 29 to greatly restrict the vertical rise ofthe foam. This also tends to move the foamable material outwardly towardthe edges of the fibrous layers l6 and 48 to a greater extent thanotherwise.

The foamable material reaches a stringy state a distance after it movesbeyond the conveyor 62. In this 1 state, if the foam is touched by anobject and the object is pulled away, the foamable material will form'astring or strings therwith. Shortly before the foamable material reachesthe stringy state, the combination of the foamable material and fibrouslayers is directed between lower and upper belt conveyors 72 and 74having adjacentbelt runs 76 and 78. These are spaced apart a distanceless than the thickness the foam would otherwise reach if allowed toexpand unrestrictedly. One or both of the belts-72 and 74 also can bedriven to move the foam and fibrous layer combination along the line 10.The belts 72 and 74 are of sufficient length that the foam will haveprogressed through the tackfree state and will have reached its finalrise by the time it is discharged from between the runs 76 and 78 of theconveyor. Subsequently, foam slabs or bodies 80 knife or other cuttingdevice 82.

FIG. 2 shows fibers 84 of the fibrous layers 16 and 48. The fibers arerelatively long, having lengths in a range of inch to 2 inches. A closeexamination of the reinforced foam bodies indicates that these longerfibers tend to be disposed along the cell walls of the foam, rather thanpiercing the cell walls and extending through the cells as occurs withshorter fibers. It has also been found that in the final foam product,the glass fibers should be present in an amount of 0.6 0.8 pounds pcf.If the amount of fibers exceeds this range,

able material 30 is deposited on the layer 16. This distance is slightlyunder four feet because the cream time the foam will collapse. Lesseramounts of fibers can also be used, as low as about one-third of theaforesaid amount. With the lesser amounts of fibers, however, the .finalproduct will not have fibres concentrated at the surfaces or fibersthereof. The fiber diameter is also important in the combination.Relatively course fibers are desired for this purpose, in a range of0.00080 to 0.00300 inch. If fibers of smaller diameter are employed inthe desired concentration of 0.6 0.8 pounds of fibers per cubic foot offinal product, there will be insufficient free area in the fibrous layeror pack for the foam and the foam will collapse. 7 I

The fibers 84 in the layer or pack are held together by a binder 86which tends to be' concentrated at the intersections of the fibers 84,FIG. 2. The type of binder used is important so that it will provide alink between the fibers 84 and vthe foamable material. With urethaneplastic foamable material, a urea-based binder is preferred to providethe desired interlock. Binders of an acidic nature are unsuitable sincethey tend to repel the foamable material. 1

FIG. 3 shows the fibers 84 with foamable material 30a in the cream stateas the combination exists on the line 10 between the main conveyor belt29 and an upstream portion of the conveyor 62. In this state, thefoamable material has penetrated the fibrous pack in the form of the twolayers 16 and 48 but has not begun to foam to any extent. At this time,the foamable material exists primarily around the fibers 84, encasingthem, as shown.

FIG. 4 shows the fibers 84 with foamable material 30b shown in astate'after substantial foaming has occurred at a location along theline 10 substantially downstream of the conveyor 62. During foaming, thefoamable material 30a in the cream state moves outwardly from the fibers84 to the interstices therebetween to form cells 88 in the intersticeswith the fibers 84 being primarily in the cell walls and not penetratingthe cells. This location of the fibers provides a more closed cellstructure which provides better strength and lower vapor permeability. 1I

A representative example of a foam and its various states in relation tothe line 10 of FIG. 1 will be set forth for illustrative purposes. Aurethane foam reaches the cream state seconds after the components aremixed and foaming of the foamable material begins substantially at thistime. The foam reaches a 50% rise in 40 seconds and reaches the stringystate after 50 seconds. After 55 seconds the foam becomes tack-free butcontinues to rise, if unrestricted, until foaming is completed after 70seconds. Assuming that the conveyor of the line 10 moves the foam andfibrous layer combination at a speed of twelve feet per minute, thefirst roller 64 of the conveyor 62 will be slightly less than four feetbeyond the pour point, the location at which the foamis timed from themixing of the components at the source 36 after which the mixture takesa few seconds to reach the upper surface of the layer 16. In thisinstance, the conveyor 62 will be about 2 feet long so that the foam hasreached approximately a 25% rise by the time it moves beyond thedownstream conveyor roller 66. The conveyors 72 and 74 will be aboutnine feet beyond the pour point and will extend for at least five feetalong the line 10 to assure that the foaming is complete by the time thefoam body 80 is discharged from between the conveyors 72 and 74.

The combination of foam and fibrous layers is schemati'cally shown at 90in FIG. 5 in the state as the combination reaches the conveyor 62. Here,the foamable material has not yet been distributed into the fibrouslayers 16 and 48 and foaming has not commenced.

FIG. 6 shows the final fiber-reinforced slab or body 80 shortly beforeemerging from between the belt runs 76 and 78. A foamed material 92results after the foamable material 30 has been foamed or risen tocompletely fill the distance between the conveyor-runs 76 and 78. Withthe foam rising primarily in a vertical direction, cells 94 formed inthe foam are elongate with their longitudinal or major dimensionsextending generally perpendicular to the main surfaces of the slab 80.

Fibers indicated at 96 in FIG. 60f the layers 16 and 48 are orientedgenerally parallelto the major surfaces of and also between the conveyorruns 76 and 78. The.

elongate cells 94 provide substantial strength for the foam slab in thevertical direction but leave the foam weaker in a horizontaldirection.Here, however, the weakness is overcome by the fibers 96 which providehorizontal strength for the foam. Consequently, the foam slab 80 nolonger exhibits a directional strength or weakness but is strong in alldirections. Both compressive and flexural strength are increased by thefiber orientation.

Plastic foam slabs or bodies also tend to exhibit a low impactresistance or compressive strength at the surfaces. To overcome orreduce this tendency, a foam slab or body indicated at 98 in FIG. 7can'be made. In this instance, the slab 92 is made with glass fiberslocated in layers which have fewer or smaller interstices than thelayers 16 and 48. The foamable material thus has lesschance to penetrateor pass through the fibrous layers during foaming. Consequently, whenthe foamable material 30 rises, it tends to carry or push fibers 100 inthe layers toward the major surfaces of the slab with a concentration ofthe fibers 100 thereby resulting near the major surfaces thereof. Thecentral portion of the foamed plastic can have glass fibers in an amountof 5l5%, by weight, with the fiber concentration at the surface or skinportions being 30-50%, by weight. This concentration of fibers providesgreater impact resistance at the surfaces of the slab and the foam alsohas a lesser tendency to absorb moisture. The surface concentration ofthe fibers can also be achieved by using layers of fibers similar to thelayers 16 and 48 but with the fibers initially concentrated at the lowersurface of the layer 16 andat the upper surface of the foam cells 'sothat a denser foam also results near the surfaces.

A concentration of fibers at the major surfaces of a slab or body canalso be achieved in a slab or body 102 of FIG. 8. In this instance,instead of the concentration of the fibers at the surfaces, as shown inFIG. 7, fibrous mats 104 and 106 are employed at the surfaces with thesebeing used, if desired, in place of the flexible sheets 12 and 52. Thefoam in'this case, as it rises, penetrates interstices in the mats 104and 106 to provide an integral product again having high impactresistance at the surfaces along with the lower water and vaporabsorption characteristics. The mats 104 and 106 can be of woven ornon-woven fibers, preferably the latter.

Roof insulation embodying the invention is shown in FIG. 9. Accordingly,insulation indicated at 108 includes a glass fiber-reinforced foam slab110, a lower glass fiber layer or board 112, and an upper layer or mat114 of glass fibers. The lower fibrous board 112 provides fireresistance for the insulation 108 while the foam slab 110 provides goodthermal insulation. The upper mat 1 14 provides protection for theplastic foam of the slab 110 whenhot asphalt or the like is applied tothe upper mat 114. The foam slab 110 can be formed in situ on the board112 but a coating or layer 116 of latex paint or other suitable materialincorporating an inorganic filler is preferably first applied to theboard 112. This reduces the extent of penetration of the foamablematerial into the board 112 which results in waste of the foam. With thecoating 116, penetration is still sufficient to provide an excellentbond between terial, the supply of the foamable material being small sothat the dwell time of the foamable material in the receptacle 128 isshort. The two layers 124 and 126, the former now being impregnated withthe foamable material, then pass between a pair of guide and squeezerolls 132 and 134 which guides them onto the pipe 122 and compressesthem somewhat so that some of the foamable material penetrates the outeror upper layer 126 to some degree. As foaming of the foamable materialprogresses, the layers or strips move beneath an endless compressionbelt 136 which restricts the foaming of the foamable material to someextent. The foamable material also penetrates the adjacent wraps of thestrips so that a substantially integral final insulating layer 138results on the pipe 122. The compression belt 136 is guided and woundaround a plurality of rolls 140, one of which can be driven to enablethe compression belt 136 to move with substantially the same peripheralspeed as the outer surface of the insulation 138.

FIG. 12 schematically shows in perspective apparatus for applyingcompressive forces tovthe foam-fiber comthe slab 110 and the board 112.The mat 114 can be applied over the foamable material and reinforcingfibers at the time, or before, foaming commences, with the mat 114taking the place of the paper layer 52, if desired. Penetration'of thefoamable material into the mat 1 14 also occurs to provide agood bondwhich prevents the possibility of the mat being peeled off the foam slab110 when the hot asphaltis mopped on.

Roof insulation 118 of FIG. 10 is similar to that of FIG. 9 except thata lower mat 120 of glass fibers is substituted for the lower fibrousboard 1 12. The overall insulation of FIG. 10 can thus be thinner thanthat of FIG. 9 or the foam slab 110 can be thicker. The insulation 118does not have the fire resistance of the insulation 108 but is used onconcrete or structures of similar fireproof, non-conducting material. Aneffective bond is achieved between the reinforced plastic foam slab andthe mats 114 and due in part to the fiber reinforcement of the plasticfoam. In some instances, a slab having a skin with concentrated fibers,as shown in FIG. 7, may be used in place of the slab 110 with the uppermat 114 of FIG. 9 or 10 then no longer being needed.

Insulation for pipe or a storage tank, by way of example, can be appliedwith the apparatus schematically shown in FIG. 11. In this instance, a.pipe 122 can be rotated in the direction of the arrows and advancedtoward the righLTwo layers or strips 124 and 126 of fibers supplied froma suitable source (not shown) are spirally wrapped around the pipe 122as the pipe is'rotated and advanced. The lower fibrous layer 124 isdirected into a receptacle 128 into which foamable material is suppliedfrom a source (not shown), this material being similar to the material30 of FIG. 1, for example. The lower layer 124 moves under a guide roll130 so that the layer 124 is fully immersed in the foamable mabination,this apparatus being used in place of the conveyor 62 and its relatedcomponents. Whereas-the conveyor 62 applies uniform and preferablyslight compressive force the foam-fiber layer, the apparatus of FIG. 12applies the compressive forces in a nonuniform, concentrated manner ineffect to knead the foam-fiber combination to achieve mixing thereof.The combination of the carrier sheet 12, the fibrous layer 16, thefoamable liquid 30, the fibrous layer 48, and the upper sheet 52 aredirected between the lower supporting roll 60-and an upper compressiveroll 142.'The' compressive roll 142 actually consists of two or moreindividual rolls 144 which have projections or cleats 146 thereon tofacilitate kneading and thorough mixing of the foamable material and thefibers of the fibrous layers. In a preferred form, the individual rolls144 are rubber tires having treads thereon, with the tires being of alow-profile, low-pressure type. The rolls 144 are rotatably mounted onan axle 148 suspended by supports 150 which can be vertically adjusted.The projections of the rolls provide concentrated compressive forces onthe combined foam-fiber layer, which causes thorough mixing and wet outof the fibers by the foamable material..The projections can also helpspread the foam outwardly toward the edges of the fibrous layers. Ifdesired, additional rolls or tires can be located downstream of therolls 144 and positioned on a line between the rolls 144 to knead thefoam-fiber combination tending to pass through any space or gaps betweenthe rolls 144. 1

Referring to FIG. 13, additional modified apparatus for applyingcompressive forces to the foam-fiber combination is shown somewhatschematically. In this instance, four rolls 152 are shown, beingrotatably supported on pivoted arms 154. The arms 154, in turn, arepivotally supported by four spokes 156 rotatably mounted on an axle 158.The arms 154 have setscrews connected between them and the spokes 156 tolimit movement of the arms and the rolls downwardly toward thefoam-fiber layer. The spokes 156 are driven in a counterclockwisemanner, as shown, by suitable means including a driven sprocket 162, achain 164, a drive sprocket 166, and a motor 168. With this direction ofrotation, the rolls 152 move in the same direction as the foam-fibercombination but at a faster speed. I

The roll assembly and the drive are mounted on a platform 170 pivoted byan axle 172 to a framework 174. A pneumatic cylinder 176 connects aportion of the frame 174 to the platform 170. By varying the amount ofpressure supplied to the rod end of the cylinder 176, and by adjustingthe setscrews 160, the extent of the contact of the rolls 152 on thefoam-fiber combination can be controlled. The rolls 152 preferably applysubstantially uniform pressure over the foamfiber layer as they movethereover, with the extent of the contacts of the rolls with the layerbeing such as to overlap somewhat.

The rolls 152 again provide somewhat concentrated forces on thefoam-fiber combination, these forces being somewhat more uniform thanthose provided by the projections 146 of the rolls 144. However, thearrangement of the rolls 152 has an advantage over the conveyor 62 ofFIG. 1. With the conveyor 62, it is possible for the foam appliedbetween the fibrous layers to build up in front of the conveyor 62. Ifthis is sufficient, the foam is delayed to the point that it begins tofoam along the built-up line prior to its intended location. However,with the arrangement of the rolls 152, such build-up cannot occur in thefoam-fiber layer and this potential problem is eliminated.

Various modifications of the above-described embodiments of theinvention will be apparent to those skilled in the art, and it is to beunderstood that such modifications can be made without departing fromthe scope of the invention, if they are within the spirit and the tenorof the accompanying claims.

We claim:

1. A method for producing a body of fiber-reinforced foam comprisingsupplying a first layer of fibers, supplying a foamable materialsubstantially uniformly to one surface of said layer, supplying a secondlayer of second flexible sheet adjacent an outer surface of said secondfibrous layer, applying compressive force to the resulting compositelayer to enable the foamablematerial to penetrate into the fibrouslayers, and limiting the maximum distance the flexible sheets can moveapart to restrict the extent of the foaming of the foamable material.

2. The method according to claim 1 characterized by applying thecompressive force in a non-uniform. concentrated manner to knead thefoamable material in the fibrous layers.

3. A method for producing a body of fiber-reinforced foam comprisingsupplying a layer of fibers, supplying a foamable material substantiallyuniformly to one surface of said layer, applying compressive forces in anonuniform, concentrated manner to the composite layer to knead thefoamable material into the fibrous layer to cause the foamable materialto penetrate into the fibrous layer, and limiting the maximum distancethe outer surfaces of the layer can be moved apart to restrict theextent of the foaming of the foamable material.

4. A method according to claim 3 characterized by applying thecompressive forces by rotating a roll above the composite layer having aplurality of projections thereon engagable with the composite layer asthe roll is rotated.

5. A method according to claim 3 characterized by applying thecompressive forces to the composite layer by positioning a plurality ofrolls above the composite layer and by rotating the rolls in a circularpath about a common axis to move the individual rolls sequentially intocontact with the composite layer.

6. A method according to claim 1 characterized by applying thecompressive force through a roll above the composite layer having aplurality of projections thereon. I

7. A method according to claim 1 characterized by applying thecompressive force by positioning a plurality of rolls above and incontact with the composite layer and by rotating the rolls.

1. A METHOD FOR PRODUCING A BODY OF FIBER-REINFORCED FOAM COMPRISING SUPPLYING A FIRST LAYER OF FIBERS, SUPPLYING A FOAMABLE MATERIAL SUBSTANTIALLY UNIFORMLY TO ONE SURFACE OF SAID LAYER SUPPLYING A SECOND LAYER OF FIBERS AND PLACING SAID SECOND LAYER IN CONTACT WITH THE ONE SURFACE OF THE FIRST LAYER WITH THE FOAMABLE MATERIAL THEREBETWEEN, SUPPLYING A FLEXIBLE OUTER SHEET ADJACENT AN OUTER SURFACE OF SAID FIRST FIBROUS LAYER SUPPLYING A SECOND FLEXIBLE SHEET ADJACENT AN OUTER SURFACE OF SAID SECOND FIBROUS LAYER, APPLYING COMPRESSIVE FORCE TO THE RESULTING COMPOSITE LAYER TO ENABLE THE FOAMABLE MATERIAL TO PENETRATE INTO THE FIBROUS LAYERS, AND LIMITING THE MAXIMUM DISTANCE THE FLEXIBLE SHEETS CAN MOVE APART TO RESTRICT THE EXTENT OF THE FOAMING OF THE FOAMABLE MATERIAL.
 2. The method according to claim 1 characterized by applying the compressive force in a non-uniform, concentrated manner to knead the foamable material in the fibrous layers.
 3. A method for producing a body of fiber-reinforced foam comprising supplying a layer of fibers, supplying a foamable material substantially uniformly to one surface of said layer, applying compressive forces in a non-uniform, concentrated manner to the composite layer to knead the foamable material into the fibrous layer to cause the foamable material to penetrate into the fibrous layer, and limiting the maximum distance the outer surfaces of the layer can be moved apart to restrict the extent of the foaming of the foamable material.
 4. A method according to claim 3 characterized by applying the compressive forces by rotating a roll above the composite layer having a plurality of projections thereon engagable with the composite layer as the roll is rotated.
 5. A method according to claim 3 characterized by applying the compressive forces to the composite layer by positioning a plurality of rolls above the composite layer and by rotating the rolls in a circular path about a common axis to move the individual rolls sequentially into contact with the composite layer.
 6. A method according to claim 1 characterized by applying the compressive force through a roll above the composite layer having a plurality of projections thereon.
 7. A method according to claim 1 characterized by applying the compressive force by positioning a plurality of rolls above and in contact with the composite layer and by rotating the rolls. 